The vaccine candidate, RTS,S, is produced in yeast cells and targets the Plasmodium falciparum malaria parasite, most common in sub-Saharan Africa. It uses GSK’s proprietary AS01 adjuvant system, containing QS-21 Stimulon adjuvant licensed from Antigenics, a subsidiary of Agenus, as well as monophosphoryl lipid A (MPL) and liposomes.
RTS,S is designed to prevent P falciparum from infecting, maturing and multiplying in the liver, by triggering the body’s immune system when the parasite first enters the human host’s bloodstream or infects liver cells.
A spokeswoman for GSK told BioPharma-Reporter “Given that – if approved – this would be the first vaccine against a human parasite, we’re hopeful it could open doors for researchers to apply the technology elsewhere.”
The company said the eventual price of RTS,S will cover the cost of manufacturing the vaccine, plus “a small return of around 5 per cent that will be reinvested in research and development for second-generation malaria vaccines, or vaccines against other neglected tropical diseases.”
Its submission will follow the EMA’s Article 58 procedure, a pathway which assesses drug candidates manufactured in the EU for a disease deemed a major public health interest by the WHO, and intended exclusively for use outside the EU.
This assessment, performed by the EMA and the WHO, requires drugs and vaccines to meet the same standards as those intended for use within the EU.
If RTS,S receives approval, WHO has said it could establish a policy recommendation by the end of 2015, a formal review process which instates immunisation schedules for diseases with a global public health impact.
Approval by the EMA would also be the basis for marketing authorisation applications to national regulators in sub-Saharan Africa. Most African countries require a review by the EMA before registering sanctioning a drug or vaccine manufactured in Europe.
GSK has invested more than $350m (€260m) in RTS,S’s R&D and says it expects to invest a further $260m until development is completed. The vaccine received financial and scientific help from the PATH Malaria Vaccine Initiative (MVI), a programme established by the Bill & Melinda Gates Foundation.
In its Phase III efficacy trial, RTS,S was administered in three doses, one month apart.